The invention relates to devices for holding workpieces, for example, gears, to permit the honing of an axial center bore in the workpiece.
In a known device of this type, the workpiece is held during honing by a work holder plate floatingly supported transversely to the tool axis, with a plurality of work holder plates being arranged in the axial direction of the honing tool one above the other. To hold workpieces, the work holder plates are provided with a recess adapted to the size and configuration of the workpieces, the recess being open toward the front side of the work holder plate. From this front side, the workpiece may be inserted in the recess until the bore to be machined is approximately in the axis of the honing tool. The workpiece rests with an axial front surface against a shoulder provided within the recess, and is clamped in this position by two clamping chucks arranged opposite to each other under spring pressure and acting on the front side. After machining, the chucks are moved against the force of the spring to release the workpiece, whereby the workpiece is set free and may be taken from the fixture. For secure, twist free transfer of the machining torque a very high clamping force is required, which could lead to elastic deformations of the workpiece. Machining accuracy is therefore considerably reduced.
In another known device, a holding pin is provided which engages a gap of the gear teeth. Since, however, as the result of the unilateral torque support, a residual center force is created which urges the workpiece out of its set position. This device similarly is not suitable for the attainment of high working accuracies. Furthermore, in devices of this type, the workpieces tend to tilt under the effect of the axial machining forces. These two conditions significantly affect the machining accuracy, with consequent detrimental affect on the quality of the workpiece.